During Gwangjong's reign, medical centres known as Daebi-won, which provided free medicines to poor patients, were set up in Kaesong and Pyongyang, later expanding in the provinces as the Hyeminguk(public health department). Taejo had established regional granaries to face the times of drought, and Gwangjong added jewibo, stores which charged interests on grain loans, which were then used for poor relief. These measures, even if in modified forms, kept on working for the next 900 years, parallel to better cultivation methods to keep up with the growth of population.